Porous membrane reactors typically utilize a bulk porous media which is affixed to the end of stainless steel tubing through which the chemical species is delivered. For the application of steam reforming hydrogen containing fuels, a catalyst is introduced to the porous membrane and the entire fixture is heated as gas is delivered to the membrane. While steam reforming of methanol has been reported at 350° C., typical operating temperatures are high, e.g., 500° C. to 700° C. due to the inability of the reactor to adequately exchange heat with the outside environment.
German patent application, DE 1998-19825102 discloses a method to produce catalytic microreactors that includes “placing a catalyst in the reaction spaces.” The microreactors can be used for steam reforming or partial oxidation of hydrocarbons to produce hydrogen gas for fuel cells.
Srinivasan et al disclose in the American Institute of Chemical Engineers (AIChE) journal (1997), 43(11), 3059-3069, a silicon-based microfabrication of a chemical reactor (microreactor) having submillimeter flow channels with integrated heaters, and flow and temperature sensors. The article discusses the potential applications of this reactor and the feasibility of a variety of operating conditions.